Accept hyphen and plus sign in emoji detection

Fixes #5635

parser/pageparser/pagelexer.go

@@ -223,7 +223,7 @@ func lexEmoji(l *pageLexer) stateFunc {
 			break
 		}
 		r, _ := utf8.DecodeRune(l.input[i:])
-		if !isAlphaNumeric(r) {
+		if !(isAlphaNumericOrHyphen(r) || r == '+') {
 			break
 		}
 	}